CooperParlee

So, I've been working with creating a custom entity and that's going fairly well. Unfortunately, I cannot find the necessary methods to spawn entities procedurally during world generation. All of the methods that Minecraft uses to register entities in vanilla are protected methods, so I can't use those. I also have struggled to find reputable source code to take a look at on GitHub for registering entities to world spawning for 1.15.2, as it seems to be very different from previous versions. Is it possible that someone could refer me to a repo that does it elegantly or just to the necessary methods I should use? Thanks